On the Distribution, Relative Abundance and Protection of Tortoises in Bulgaria
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TRANSLATIONS Editorial Introduction The following paper on tortoises in Bulgaria by Vladimir A. Beshkov was originally published in the Bulgarian Academy ofSciences in 1984. Despite its being nine years old, we have published it for three reasons: because few tortoise biologists are fluent in Bulgarian; because the paper is an important and unusually thorough one; and because the study utilized a technique that may well be applicable to othercountries undertaking nation-wide tortoise surveys. The use ofwidespread standarized questionnaire data with follow-up site visits and transects in a selected sample of localities makes it possible to obtain data, not only on the current relative abundance of tortoises, but also on past abundance, at least within human lifetimes. The methodology would obviously be of more limited applicability in areas where tortoises were highly cryptic orlived in burrows, or where human habitation was scant orabsent, orwhere there was a need to differentiate between very similar species of tortoises. The translation project derived from a meeting between James R. Buskirk and the author, Vladimir A. Beshkov, in May, 1991, at which Dr. Beshkov expressed interest in bringing his paper before a wider audience. Buskirk arranged for a Bulgarian-English professional translator to prepare a literal translation, and this was then reworked by Buskirk, with input from David Jameson and Peter Pritchard to produce the version published here. Chelonian Conservation and Biology, 1993.1(1):53-62 €) 1993 by Chelonian Research Foundation On the Distribution, Relative Abundance and Protection of Tortoises in Bulgaria VLADIMIR A. BESHKOV1 IInstitute ofZoology, Bulgarian Academy ofSciences, Sofia, Bulgaria [Originally published in Bulgarian in 1984; Ekologiya (Sofiya) 14:14-34] Translation arranged by JAMES R. BUSKIRK ABSTRACT. - The present day distribution and relative abundance oftortoises (Testudo graeca ibera andTestudo hermanni) in Bulgariaareshown inFig. 1 and the regions where they were exterminated recently in Fig. 4. The ubiquitous reduction in tortoises' abundance is due to intensified agriculture, alterations in low-rise forests thatare turned into pastures, coniferous forests, etc., and notso much to the effects oflargeindustries,urbanizationanddirectconsumption bypeople,thelatteroccurring mostly in Plovdiv and its vicinity. During 1945 through 1959 tortoises were being collected mostly in the eastern part of the country where they used to be abundant. During 1960 through 1969 deliveriesfrom this partdiminished while deliveries from western Bulgariastarted growing steadily until 1979. Insome areas particularlyin northwestern Bulgariaand the Eastern Rhodopesjuveniles are being consumed by wild boars, thus reducing the total abundance. The protection of tortoises should be intensified by raising public awareness of their status as protected animals (under ordinance 128/1981 by the State Committee onEnvironmental Protection) and discontinuing illegal collection by poachers and tourists. Accelerated economic development in Bulgaria, and in lations throughout the country, to investigate reasons for particular the introduction ofintensive agriculture in recent local decline or disappearance of tortoises, and to propose decades, has caused substantial alteration of both lowland scientifically sound conservation measures. and upland habitats in the country. This has resulted in negative impacts upon the distribution and abundance of METHODS most species ofBulgarian fauna. Among the forms affected are the two tortoise species, Testudo hermanni Gmelin and The data for this study were obtained by means of Testudo graeca ibera Pallas. The collection of tortoises for questionnaires distributed to all communities throughout food has also contributed to the rapid decline ofpopulations Bulgaria (with the exception ofscattered villages with fewer in some areas and their total disappearance in others. than 20 inhabitants). The questionnaires, explaining the This study was conducted jointly by the National Com purpose of the survey and the importance of responding, mittee for Nature Conservation and the former National solicited data pertaining to the tortoises only from the Council ofthe Fatherland Front. Its aim was to determine the territory surrounding the specific community (town or vil distribution and the past and present status oftortoise popu- lage) surveyed. The survey was conducted between late 54 Chelonian Conservation and Biology, Volume 1, Number 1 (1993) EB1.2~:15 ~3 i§6 m4 ml7 Figure 1. Distribution of tortoises in Bulgaria. Region I, no tortoises in high mountainous plateaus; 2, small isolated populations up to 15-30 years ago; 3, tortoises completely extirpated; 4, low tortoise densities; 5, moderate tortoise densities; 6, relatively undisturbed tortoise populations; 7, high tortoise densities. 1976 and the end of 1979. translations ofthe original Cyrillic letters]. Category A ("no The questionnaire technique was selected after consid tortoises around this settlement, either now or in the past") eration ofthe following: i) Comprehensive field studies on included 786 of the responses (21.96%). Categories B, C, tortoise population densities were not possible, simply be and D were defined as "no tortoises found presently, but cause ofthe sheer magnitude ofthe task; and ii) The survey occurred here 30, 15, or 5 years ago, respectively". Category method was the only practical method ofgathering informa B included 109 responses (3.04%); Category C 265 re tion about past distribution and abundance of tortoises, and sponses (7.39%), and Category D 78 responses (2.17%). human use ofthe tortoises during recent decades, including Together, 452 responses (12.60%) alluded to tortoisespresent the use of tortoises for food. in the past, but no longer. The method employed did not differentiate between the Tortoise density was estimated in a given territory by two tortoise species, so the data for both are combined. The means of the question "how many tortoises would you find following considerationsjustify this approach: both species if you went out on a spring day in the best tortoise area?", chiefly occupy the lowlands and are sympatric almostevery responses being classified as a) probably none; b) up to 2 where they occur (Kovachev, 1912; Buresh and Tsonkov, specimens- (607 responses, 16.93%); c) between 3 and 10 1933; Beshkov, 1961), and differences in their biology are (1038 responses, 28.95%); d) between 11 and 25 (397 minor. Moreover, the factors affecting distribution and num responses; 11.07%); and e) more than 25 (305 responses; bers apply to both species equally. People gathering tor 8.50%). toises for food expressed no preference for one or the other The information obtained was plotted on a black and species, so conservation/preservation problems are identi white map of Bulgaria with a scale of 1:300,000, with the cal. These sociological considerations dictated ourpolicy of rivers, settlements, and boundaries of adjacent territories pooling the data for the two species. indicated. All territories giving the same category of re Questionnaires were circulated to 4495 settlements, sponse were denoted in the same color. In the resulting and a total of 3585 responses were received (79.75%). Of mosaic, territories of a given color (i.e., a given range of these, a total of57 gave "no answer", or included contradic tortoise densities) were clearly grouped, allowing conclu tory data, or were otherwise unusable. ' sions to be drawn about the relative density oftortoises over In 1347 cases (65.46%), respondents confirmed the wider areas. Dataprocessing and map preparation were ably presenceoftortoises; the remaining 1238 (34.53%) reported assisted by B. Vassilev, L. Stanimirova, B. Grigorov, andG. no tortoises. Responses were allocated to one of eight Petrova, to whom I extend my gratitude. categories, the first four (A, B, C, D), being the negative In order to establish an index to the reliability ofthe data ones, and the remainder (E, F, G, H) the positive ones [Ed. obtained in the questionnaires, we personally surveyed Thefirst8 English letters, A-H, have been substitutedforthe tortoises in 111 settlement territories - 9 in the Danubian first 8 Cyrillic letters actually used, as opposed to direct Plain, 18 in the Balkan Range region, 50 in the Thracian Chelonian Conservation and Biology, Volume 1, Number 1 (1993) 55 ~------jA ~B 00000 ~D ~E ~F ~G r---l _-:-c:-= ~ 00 oOoC ~ ~ ~ ~ ~H Figure 2. Distribution and relative numbers oftortoises in the central part ofthe Upper Thracian Plain. A="No known tortoises at present or before" territories; B = "Tortoises known up to 30 years ago"; C = "Tortoises known up to 15 years ago"; D = "Tortoises known up to 5 years ago"; E =Territories with up to 2 tortoises per day trip; F =Territories where between 3-10 tortoises can be seen per day trip; G =Territories where between 11-25 tortoises observed per day trip; H =Territories with no data on tortoises. Plain and Sredna Gora region, and 34 in the region of Rila questionnaire data, although 3 were below the lower end of and the Rhodopes. the range. Someofthe interviewees believedthatthefIgures In the 19 Category A settlements we visited, multiple given in the questionnaireoverstated the numberoftortoises interviews confIrmed the numbers obtained by the survey. that would actually be encountered. Insettlements ofCategoriesB,C, andD (12 settlements),we Twelve settlements in Category H were visited, and established, through